By Jeff Haden of Inc Magazine While it's really hard to immediately win over a crowd, it's really easy for a speaker to lose the room within the first few minutes of a presentation. To make sure you don't lose your audience, here's Boris Veldhuijzen van Zanten, serial entrepreneur and founder of TwitterCounter and The Next Web, with ten things you should never say during your presentations:1. "I'm jet-lagged/tired/hungover." Not sure where this comes from, but one in five presentations at any conference starts with an excuse: "They only invited me yesterday," or, "I'm really tired from my trip," or some other lame excuse the audience really doesn't want to hear. We, the audience, just want to see you give it your best. If you feel like crap and can't give it your best, maybe you should have cancelled. Take a pill, drink an espresso and kill it!2. "Can you hear me? Yes you can!" This is how many people start their talks. They tap a microphone three times, shout, "Can you all hear me in the back?" and then smile apologetically when it becomes clear that, yes everybody can hear them, but no one raised their hand. It isn't your responsibility to check the audio. There are people for that. (And if there aren't, test the volume ahead of time.) But if you do speak into the microphone and get the impression it's not working, just relax, count to three, and try again. If you still think the sound isn't working, calmly walk to the edge of the stage and discreetly ask the moderator to check for you. Throughout, smile at the audience and look confident. Assume everything works until proven otherwise, then stay calm and wait for a fix.3. "I can't see you because the lights are too bright." Yes, when you are on stage the lights are bright and hot and it will be difficult to see the audience. But they don't have to know about all that. Just stare into the dark, smile often, and act like you feel right at home. Feel free to walk into the audience if you want to see them up close. And don't cover your eyes to see people but politely ask the lights person to turn up the lights in the room if you want to count hands or ask the audience a question. Even better, talk to the lights people in advance so they know when you will ask them to raise the lights.4. "I'll get back to that later." If you happen to stumble on an audience eager to learn and interact, grab that chance and enjoy it. If someone has a question you will address in a later slide just skip to it right away. If someone is brave enough to raise their hand and ask you a question, compliment them and invite the rest of the audience to do the same. Never delay anything.5. "Can you read this?" The common rule is to make the font size on your slides twice the size of the average age of the audience. Yes, that means that if you expect the audience to be 40 then on average you are stuck with a font size of 80 points. You won't be able to fit a lot of text on the slide, which is a good thing and brings us to the next point.6. "Let me read this out loud for you." Never ever, ever, ever in a million years add so much text to a slide that people will spend time reading it. And if you do, make damn sure you don't read it out loud for them. The best way to lose your audience's attention is to add text to a slide. Here's what happens when you have more than four words on a slide: people start reading it. And what happens when start reading? They stop listening to you. Only use short titles on slides, and memorize any text you want the audience to read. Or, if you must include an awesome three-sentence quote, announce that everyone should read the quote and then be quiet for six to ten seconds so they can actually read it.7. "Shut off your phone/laptop/tablet." Once upon a time you could ask an audience to shut off their devices. Not anymore. Now people tweet the awesome quotes you produce or take notes on their iPads. Or they play solitaire or check Facebook. You can ask for the audience to turn their phones to silent mode, but apart from that you just have to make sure that your talk is so incredibly inspiring they will close their laptops because they don't want to miss a second. Demanding attention doesn't work. Earn attention instead.8. "You don't need to write anything down or take photos; the presentation will be online later." It is really cool that you will upload your presentation later. But if it's a good presentation it won't contain too many words (see point 4) and won't be of much use to the audience. For many people the act of writing is an easy way to memorize something they've heard. In short, allow people to do whatever they want during your presentations.9. "Let me answer that question." Of course it is awesome if you answer a question right away, but you need to do something else first. Often the question from an audience member will be clear to you but not to the rest of the audience. So please say, "I'll repeat that question first so everybody can hear it," and then answer it. Plus, when you make a habit of repeating questions, that gives you a little more time to think of an awesome answer.10. "I'll keep it short." This is a promise no one keeps. But a lot of presentations start that way! The audience really doesn't care if you keep it short or not. They've invested their time and just want to be informed and inspired. So say, "This presentation is going to change your life," or, "This presentation is scheduled to take 30 minutes, but I'll do it in 25 minutes so you can go out and have a coffee earlier than expected." Then all you have to do is keep that promise, which brings me to the last point.Bonus tip: "What, I'm out of time? But I have 23 more slides!" If you come unprepared and need more time than allowed, you've screwed up. You must practice your presentation and make it fit within the allotted time. Better yet, end five minutes early and ask if anyone has questions. If they don't, invite them for a coffee to talk one-on-one. Giving an audience five minutes back earns their respect and gratitude. Taking an extra five annoys and alienates them.Conclusion: come prepared, be yourself and be professional. The audience will love you for being clear, for being serious, and for not wasting their time.